Mattress overlay



FIG. 1 is a top plan view of a mattress overlay showing the top surfaceof our new design;

FIG. 2 is a right side elevational view of our design, with the leftside elevational view being identical thereto;

FIG. 3 is a front elevational view of the mattress overlay, with therear end view being identical thereto; and,

FIG. 4 is a bottom plan view of the mattress overlay.

The ornamental design for a mattress overlay, as shown and described.